Leptoglossus occidentalis

Taking a break from some work in the garden today, I left my Tilley Hat on the windowsill next to our back door.

Imagine my surprise when I went back into the garden and found this strange creature crawling over my hat!

I was able to identify it as the Western Conifer Seed Bug (Leptoglossus occidentalis) - a native of the western USA that seems to be spreading rapidly across the UK at present.